Changeable Velvetberry: A Tropical Flowering Shrub for Warm Climate Gardens
If you’re gardening in Hawaii or other warm tropical regions, you might have encountered the changeable velvetberry (Stachytarpheta mutabilis), a colorful flowering shrub that’s made itself at home in island landscapes. This non-native perennial brings a splash of purple-blue blooms to gardens, but like many introduced plants, it comes with both benefits and considerations worth exploring.
What Is Changeable Velvetberry?
Changeable velvetberry is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet in height. True to its shrub nature, it develops several stems from near the ground, creating a bushy appearance that can add structure to tropical landscapes.
The changeable part of its name hints at one of its more interesting characteristics – the flowers can shift in color intensity, displaying beautiful purple to blue hues arranged in terminal spikes that catch the eye and attract pollinators.
Where Does It Grow?
Originally hailing from tropical regions of Central and South America, changeable velvetberry has established itself in Hawaii, where it now reproduces spontaneously in the wild. This adaptable plant has found the Hawaiian climate much to its liking and persists without human intervention.
Garden Appeal and Landscape Role
From an aesthetic standpoint, changeable velvetberry offers several attractive features:
- Colorful flower spikes in shades of purple and blue
- Ovate leaves that provide a lush, tropical backdrop
- Multi-stemmed growth habit that creates natural screening
- Year-round interest in suitable climates
In landscape design, this shrub can serve as a mid-level planting in mixed borders, provide informal screening, or add color to naturalized tropical gardens. Its butterfly-attracting flowers make it a decent choice for pollinator-friendly landscapes.
Growing Conditions and Care
Changeable velvetberry thrives in USDA hardiness zones 9-11, making it suitable only for the warmest regions of the United States. Here’s what this tropical shrub needs to flourish:
- Sunlight: Full sun to partial shade
- Soil: Well-draining soil with good fertility
- Water: Regular watering, especially during dry periods
- Temperature: Warm temperatures year-round (not frost tolerant)
- Maintenance: Occasional pruning to maintain shape and size
The plant’s ability to establish and spread easily means it’s relatively low-maintenance once established, though this same characteristic requires some consideration regarding placement in your garden.
Should You Plant Changeable Velvetberry?
As with many non-native plants, the decision to grow changeable velvetberry involves weighing its ornamental value against its status as an introduced species. While it offers attractive flowers and supports some pollinators, gardeners committed to native plant gardening might want to consider indigenous alternatives.
For Hawaiian gardens, excellent native alternatives include:
- Native Hawaiian mint species (Stenogyne)
- Hawaiian cotton (Gossypium tomentosum)
- Native Hawaiian shrubs in the coffee family (Rubiaceae)
These natives provide similar landscape functions while supporting local ecosystems and preserving Hawaii’s unique flora.
Planting and Establishment Tips
If you decide to include changeable velvetberry in your tropical garden, here are some tips for success:
- Choose a location with morning sun and some afternoon protection in extremely hot climates
- Prepare soil with organic matter to improve drainage and fertility
- Water regularly during the first growing season to establish roots
- Prune lightly after flowering to maintain desired size and shape
- Monitor for self-seeding and remove unwanted seedlings promptly
The Bottom Line
Changeable velvetberry can be an attractive addition to warm-climate gardens, offering colorful blooms and pollinator appeal. However, as responsible gardeners, it’s worth considering native alternatives that provide similar benefits while supporting local ecosystems. If you do choose to grow this tropical import, plant it thoughtfully and maintain it responsibly to prevent unwanted spread beyond your garden boundaries.
